Power transmission device



July 19, 1966 K. G. AHLEN 3,261,232

POWER TRANSMI S S I ON DEVI CE Original Filed June 9, 1958 2Sheets-Sheet 1 July 19, 1966 K. G. AHLEN POWER TRANSMISSION DEVICE 2Sheets-Sheet 2 Original Filed June 9, 1958 United States Patent Ofi ice326L232 Patented July 19, 1956 3,261,232 POWER TRANSMHSSION DEVICE KarlGustav Ahln, Fridhemsgatan 2, Stockholm, Sweden Qontinuation ofappiication Ser. No. 741,203, June 9, 1958. This application Apr. 27,1964, Ser. No. 365,555 3 Claims. (1. 74-732) This application is acontinuation of my pending application Serial No. 741,208, nowabandoned, filed June 9, 1958, the latter application being acontinuation-in-part of application Serial No. 267,676, now abandoned,filed January 22, 1952.

The present invention contemplates a power transmission comprising acombination of a hydraulic torque braking exceeding that engine brakingeffect obtainable with the engine engaged in second gear of a four speedgear box. The invention provides for hydraulic braking of two differentbraking effects, the lesser one together with the engine braking beingcomparable to that braking effect obtainable on engine braking withengagement of the third gear of a four stage mechanical gear box.

Besides enabling this braking effect the mechanical gear systemaccording to the invention also provides for two more things, namely theuse of the turbine member of the hydraulic system for obtaining a doublerotation system which gives a very high torque multiplication at lowspeeds of rotation of the secondary shaft of the hydraulic torqueconverter, and also that the braking of the secondary shaft of thetorque converter to a complete stop is made possible without furthercomplications, consisting of braking or synchronizing members or thelike, so as to enable shifting from one drive to another of the gears ofa complementary gear box which may be connected to the secondary shaft.This braking of the secondary shaft my further be used per se forbraking of a movable mass connected to the secondary shaft.

The invention is directed towards a power trans ission and brakingdevice for connecting a driving shaft and a driven shaft. In thistransmission a hydraulic torque converter comprises a housing providinga hydraulic circuit having a first section in which the flow of theworking liquid is outwardly directed, a second section in which the flowis inwardly directed substantially radially and two return bend sectionswhich connect the sections for outwardly and inwardly directed flows. Inthis circuit are located blade rings arranged on pump, turbine andreaction members. The pump member is connected to the driving shaft andhas one pump blade ring which is located in that part of the hydrauliccircuit in which the flow is outwardly directed. The turbine member isconnected to the driven shaft and has at least two turbine blade rings.The reaction member is connected to a re action shaft and has at leastone reaction blade ring, each of which is located in that part of thehydraulic circuit in which the flow is inwardly directed. The reactionmember is further freely rotatable in relation to the housing of thecircuit. Each reaction blade ring is located between two turbine bladerings, so that one turbine blade ring is located between the outlet of areaction ring and the inlet of the pump blade ring. The transmissioncomprises further means including a reversing mechanism connecting thereaction and driven shafts for power transmission in either directionand means for controlling said reversing mechanism to drive the reactionmember in a direction opposite to that of the turbine and pump membersin order to provide a hydraulic braking effect above a speed ratiobetween the turbine and pump members at which the efiiciency of thepower transmission is zero.

The transmission may further comprise a direct drive clutch and meansfor simultaneously engaging said clutch and the means for controllingthe reversing means in order to obtain a high braking effect.

The transmission may also comprise a brake for the reaction member andmeans for engaging this separately or simultaneously with the directdrive clutch.

The transmission may further comprise a mechanical transmittingconnection between the driving and the driven shafts arranged inparallel with the hydraulic torque converter.

Further objects and advantages of the invention will be apparent fromthe following description taken in conjunction with the accompanyingdrawings wherein;

FIG. 1 is a longitudinal sectional view of a power transmissionconstructed in accordance with the invention; and

FIG. 2 is a longitudinal sectional view showing a modified form of theinvention.

FIG. 1 shows a hydraulic torque converter comprising a pump member 2, aturbine member 3, a reaction member 4 and a housing providing ahydraulic circuit I. Said circuit 1 comprises one part 49 in which theflow of fluid is substantially outwardly directed, one part 50 in whichthe flow of fluid is substantially inwardly directed, and two curvedparts 51 and 52 respectively connecting said parts 49 and St) foroutward and inward flow.

The pump member 2 comprises a blade ring located in the part 49 of thehydraulic circuit in which the flow of the fluid is substantiallyoutwardly directed and is driven by the engine shaft 9 through theflywheel 19 and a spline connection 11. The pump supports a rotatinghousing comprising the portions 12 and 13 which enclose the hydrauliccircuit of the hydraulic torque converter and the portions 12 and 14enclosing a direct drive clutch 7 for connecting the pump member withthe turbine member. The direct drive clutch 7 is arranged as a pressureliquid regulated servo-motor controlled friction clutch. The reactionmember 4 comprises a blade ring 53 located in the part 50 of thehydraulic circuit in which the flow of the fluid is substantialyinwardly directed, a disc 15 and a hollow shaft 16 on which is mounted agear wheel 17 and a brake disc carrier 18 which is a part of a brakemember 8. The turbine 3 comprises two blade rings 19 and 20 which areinterconnected by means of a side ring 21 and are located in the part 50of the hydraulic circuit in which the fiow of the fluid is substantialyinwardly directed with blade ring 19 radially outwardly and the bladering 20 inwardly of the reaction blade ring 53 so that the turbine bladering 20 is located between the outlet of the reaction blade ring 53 andthe inlet of the pump blade ring. The outlet of the blade ring 20 islocated further away from the axis of rotation than the inlet of thepump blade ring. The turbine member further comprises a disc 23 and ashaft 22. The turbine shaft 22 is arranged inwardly of the hollow shaft16. On this turbine shaft 22 there is mounted another gear wheel 24. Thegear wheels 17 and 24 are parts of a reversing gear 5. Said reversinggear 5 further comprises a suitable number of planet wheels which arecarried by a holder 26. Said holder 26 is journalled so as to be able torotate freely but may also be locked by means of the brake 6. Thereaction member shaft which is rotatably mounted on the turbine shaft 22may be held against rotation by means of the brake 8. The stationarymembers of the brake 6 and 8 are fixed to a stationary housing 27 boltedto the flywheel casing 28 and enclosing the rotating housing, thereversing gear and the brakes. The turbine shaft 22 has an extensionjournalled in an end Wall 29 which is bolted to the housing 27. Therotating housing is journalled by means of the bearing 30 on the turbineshaft and the bearing 31 on the reaction member shaft. It is sup- 3ported at 32 by the flywheel of the entire shaft. The brakes 6 and 8described above are operated by means of hydraulic servo-motors.

The transmission shown in FIG. 1 may be operated either as a continuousautomatic torque converter or as a direct drive device between the inputand output shafts of the unit. In the transmission the hydraulic torqueconverter may also be utilized as a hydraulic brake, which according tothe invenition has a very high efiiciency.

By interconnecting the pump and turbine members through the clutch 7,and simultaneously engaging the reversing gear 5 by means of the brake6, the reaction member is forced to rotate in a direction opposite thatof the pump and turbine members. If the brake 8 and the clutch 7 areengaged simultaneously and the brake 6 is released, a hydraulic brakingis also obtained as the reaction member is stationary and the pump andturbine members are rotating in the same direction and at the samespeed. This braking, however, will not be so strong as the braking withthe brake 6 and the clutch 7 simultaneously engaged. With both types ofbraking the direct drive clutch is in engagement.

If only the brake 6 is engaged and the clutch '7 and brake 8 are freethe device with the reversing gear will permit use of the blade systemof the hydraulic torque converter as a double rotation system, which ina known manner gives a high efliciency at low speed ratio between theturbine and pump members. To obtain high efficiency in the intermediatespeed range, the reaction member 4 may be stalled by means of the brake8, the brake 6 and the clutch 7 being released. Engagement of clutch 7and release of the brakes 6 and 8 enables direct drive to be effected,the whole hydraulic system rotating as a unit without effectingsignificant losses.

In a combination of a hydraulic torque converter with a rotating casingand a mechanical gear mechanism of the dog clutch type, embodying thepresent invention, the secondary or turbine member of the converter canbe stalled upon engagement of the dog clutches through simultaneousengagement of the brakes 6 and 8, which may be used as a reversing gearstep, whereby at least two of the synchronizing members are dispensedwith in the mechanical gear.

Further the advantage is gained that the release of the clutch 7 and thebrakes 6 and 8 gives a very low torque transmission in the converterwhich is advantageous for example, in a vehicle ready to start, or forsynchronizing of various gear steps in a complementary gear box workingtogether with the converter.

According to the present invention the advantages of the hydraulictorque converter have been combined with those of a mechanical gearresulting in a better efficiency than hitherto known. These advantagesof the mechanical gear mechanism include among others the possibility ofa very strong engine braking and of a high efficiency at low speedratios between the secondary and primary members. In the hydraulictorque converter according to the invention these advantages have beencombined with a continuous and automatic torque multiplication andcapability of a soft engagement of braking.

Through the combination of engine braking with different stronghydraulic braking the desired braking effect can be obtained andshifting from one braking to another may be established withoutinterrupting the braking force.

FIG. 2 shows another embodiment according to the invention,corresponding members of FIG. 1 being designated by the same numerals.

This embodiment is characterized by a reversing gear mechanism betweenthe rotatably mounted reaction member 4 and the turbine member 3, butthe turbine member is also provided with a so-called split torque devicefor transmitting torque from the engine to the turbine andsimultaneously to the output shaft. This device consists therein thatpart of the engine torque is transmitted through a gear mechanism, forexample of the planet wheel type, directly to the secondary shaft,whereas the other part of the engine torque is led to the primary memberof the hydraulic torque converter. The distribution of the torques .isdetermined by the gear ratio in this form of mechanism. At 33 is denotedthe input shaft which is driven by the engine. This shaft carries planetwheels 34 which in turn mesh with a gear rim 35 on the output shaft 36of the transmission, and also mesh with a gear rim 37 on the shaft 38 ofthe pump member 2. In this embodiment the turbine member 3 is formed asa rotating casing constituted by the end wall 39 and the housing 40containing the hydraulic system. The reaction member is provided with ashaft 41 and a gear wheel 42, which is a part of the reversing gear 5having planet wheels 43 and an outer wheel 44, provided with members 45for braking to a stop and further with the clutch 46 for connection withthe shaft 36 over the housing 39, 40. The embodiment according to FIG. 2is also provided with a clutch 48 for direct connection of the primaryshaft to the secondary shaft.

The mode of operation in this case is similar to that of the deviceshown in FIG. 1, only With that difference which will result from thedifferent design of the reversing gear 5. This reversing gear mayhowever also in this case be made similar to that shown in FIG. 1, asthe embodiment according to this figure may be replaced by that shown inFIG. 2. In the form shown in FIG. 2 the braking of the planet wheelcarrier 26 is replaced by the clutch 46 since here the planet wheels arebolted directly to the stationary casing 47.

The locking mechanism of brake 6, as shown in FIG. 1, is according toFIG. 2 replaced by the locking mechanism for the clutch 46. The lockingof the brake 8 in FIG. 1 corresponds to the brake 45 as shown in FIG. 2.

The invention is not limited to the embodiments now shown and describedbut it may be further varied in several manners within the scope of theclaims. For example a hydraulic torque converter having a stationarycasing may be used instead of one with rotating casing.

What I claim is:

1. A power transmission and braking device for connecting a drivingshaft and a driven shaft, said device comprising a rotationallystationary structure, a hydrodynamic torque converter having a rotatablymounted housing connected to and rotated by said driving shaft, saidhousing providing a hydraulic circuit having a first section in whichthe flow of the Working liquid is substantially radially outward, asecond section in which the flow of said liquid is substantiallyradially inward and radially inner and outer return bend sectionsconnecting said first and said second sections, said convertercomprising a pump member comprised of at least one ring of pump bladescarried by said housing and located in said first section of saidcircuit, a turbine member freely rotatable with respect to said housingand comprising a blade carrying part carrying at least two rings ofturbine blades located in said circuit and a shaft part co-axial withsaid housing for delivering power to said driven shaft, a reactionmember freely rotatable with respect to said housing and comprising ahollow shaft part rotatably mounted concentrically around the shaft partof said turbine member and a blade carrying part carrying one or morerings of reaction blades each located in said second section of saidcircuit and further being located between two rings of turbine blades sothat the last ring of turbine blades is located between the outlet of aring of reaction blades and the inlet of a ring of pump blades, meansincluding gearing connecting the shaft parts of said turbine andreaction members for power transmission therebetween in eitherdirection, said means further including releasable braking means foranchoring an element of said gearing to said stationary structure andsaid gearing being constructed to impose rotation in opposite directionson said shaft parts when said braking means is engaged, and clutch meanslocated on the power input side of said housing providing a mechanicalpower transmitting connection between said driving and driven shafts,said clutch means and said braking means being selectively operable,whereby to permit selective engagement of either one of said means orsimultaneous engagement of both.

2. A power transmission as defined in claim 1, in which the outlet ofsaid ring of turbine blades located between a ring of reaction bladesand said ring of pump blades is located farther away from the axis ofrotation of said power transmission than the inlet of said ring of pumpblades.

3. A power transmission as defined in claim 1 in which said reactionmember is provided with a separately operable brake, whereby to permitselective engagement of said brake and said direct drive clutch tothereby permit said brake and said direct drive clutch to be engaged atthe same time.

References Cited by the Examiner UNITED STATES PATENTS DAVID J.WILLIAMOWSKY, Primary Examiner.

DON A. WAITE, Examiner.

T. C. PERRY, Assistant Examiner.

1. A POWER TRANSMISSION AND BRAKING DEVICE FOR CONNECTING A DRIVINGSHAFT AND A DRIVEN SHAFT, SAID DEVICE COMPRISING A ROTATIONALLYSTATIONARY STRUCTURE, A HYDRODYNAMIC TORQUE CONVERTER HAVING A ROTATABLYMOUNTED HOUSING CONNECTED TO AND ROTATED BY SAID DRIVING SHAFT, SAIDHOUSING PROVIDING A HYDRAULIC CIRCUIT HAVING A FIRST SECTION IN WHICHTHE FLOW OF THE WORKING LIQUID IS SUBSTANTIALLY RADIALLY OUTWARD, ASECOND SECTION IN WHICH THE FLOW OF SAID LIQUID IS SUBSTANTIALLYRADIALLY INWARD AND RADIALLY INNER AND OUTER RETURN BEND SECTIONSCONNECTING SAID FIRST AND SAID SECOND SECTIONS, SAID CONVERTERCOMPRISING A PUMP MEMBER COMPRISED OF AT LEAST ONE RING OF PUMP BLADESCARRIED BY SAID HOUSING AND LOCATED IN SAID FIRST SECTION OF SAIDCIRCUIT, A TURBINE MEMBER FREELY ROTATABLE WITH RESPECT TO SAID HOUSINGAND COMPRISING A BLADE CARRYING PART CARRYING AT LEAST TWO RINGS OFTURBINE BLADES LOCATED IN SAID CIRCUIT AND A SHAFT PART CO-AXIAL WITHSAID HOUSING FOR DELIVERING POWER TO SAID DRIVEN SHAFT, A REACTIONMEMBER FREELY ROTATABLE WITH RESPECT TO SAID HOUSING AND COMPRISING AHOLLOW SHAFT PART ROTATABLY MOUNTED CONCENTRICALLY AROUND THE SHAFT PARTOF SAID TURBINE MEMBER AND A BLADE CARRYING PART CARRYING ONE OR MORERINGS OF REACTION BLADES EACH LOCATED IN SAID SECOND SECTION OF SAIDCIRCUIT AND FURTHER BEING LOCATED BETWEEN TWO RINGS OF TURBINE BLADES SOTHAT THE LAST RING OF TURBINE BLADES IS LOCATED BETWEEN THE OUTLET OF ARING OF REACTION BLADES AND THE INLET OF A RING OF PUMP BLADES, MEANSINCLUDING GEARING CONNECTING THE SHAFT PARTS OF SAID TURBINE ANDREACTION MEMBERS FOR POWER TRANSMISSION THEREBETWEEN IN EITHERDIRECTION, SAID MEANS FURTHER INCLUDING RELEASABLE BRAKING MEANS FORANCHORING AN ELEMENT OF SAID GEARING TO SAID STATIONARY STRUCTURE ANDSAID GEARING BEING CONSTRUCTED TO IMPOSE ROTATION IN OPPOSITE DIRECTIONSON SAID SHAFT PARTS WHEN SAID BRAKING MEANS IS ENGAGED, AND CLUTCH MEANSLOCATED ON THE POWER INPUT SIDE OF SAID HOUSING PROVIDING A MECHANICALPOWER TRANSMITTING CONNECTING BETWEEN SAID DRIVING AND DRIVEN SHAFTS,SAID CLUTCH MEANS AND SAID BRAKING MEANS BEING SELECTIVELY OPERABLE,WHEREBY TO PERMIT SELECTIVE ENGAGEMENT OF EITHER ONE OF SAID MEANS ORSIMULTANEOUS ENGAGEMENT OF BOTH.